MDEV-31355 fixup: Adjust one more test

The test gcol.gcol_purge would reliably hang on 10.6 on a
Microsoft Windows builder without this adjustment.
A similar adjustment was applied in
commit 3e40f9a7
to the tests innodb.dml_purge and innodb.instant_alter_purge.

mysql-test/suite/gcol/r/gcol_purge.result

@@ -16,7 +16,7 @@ INSERT INTO t1 (f1, f2) VALUES(1,2);
 set global debug_dbug="+d,ib_purge_virtual_index_callback";
 connection con1;
 COMMIT;
-InnoDB		0 transactions not purged
+SET GLOBAL innodb_max_purge_lag_wait=1;
 connection con2;
 commit;
 disconnect con1;

mysql-test/suite/gcol/t/gcol_purge.test

@@ -23,7 +23,7 @@ set global debug_dbug="+d,ib_purge_virtual_index_callback";
 connection con1;
 COMMIT;
 
---source ../innodb/include/wait_all_purged.inc
+SET GLOBAL innodb_max_purge_lag_wait=1;
 
 connection con2;
 commit;